The present disclosure relates to a metal mask substrate having a metal surface for resist deposition such as a metal mask substrate for use in forming a metal mask for organic EL devices, a method for controlling a metal mask substrate, a metal mask, and a method for manufacturing a metal mask.
In manufacturing of metal masks for organic EL devices, metal mask substrates in the form of a metal plate are used. A coating liquid containing materials to form a resist layer is applied to the surface to be coated of a metal mask substrate to thereby form a resist layer. The resist layer is subjected to exposure and development, so that a resist layer having a specified pattern is formed. The metal mask substrate is etched through the resist layer to thereby produce a metal mask.
In forming of the resist layer described above, the thickness of a resist layer or the in-plane thickness of a resist layer may vary in some cases, due to the variation in the amount of coating liquid to be applied to the surface to be coated or the variation in extent of drying of the coating liquid. In order to suppress such variations in a resist layer, use of a dry film resist as a resist layer has been proposed (for example, refer to Japanese Laid-Open Patent Publication No. 2013-209710).
A resist layer formed from coating liquid is a cured layer of the coating liquid applied directly to the surface of a metal mask substrate, so that a shape tracing the surface to be coated can be easily formed, and thus, the resist layer formed from coating liquid is easy to adhere to the metal mask substrate without difficulty. On the other hand, a resist layer formed from dry film resist is a layer independent layer from the metal mask substrate and adhering to a metal mask substrate surface. Therefore, the resist layer formed from dry film resist has a shape more difficult to follow the surface to be coated in comparison with a resist layer formed from coating liquid, so that a part of the resist layer may be detached from the metal mask substrate in some cases.
The above described the same circumstances apply not only to metal mask substrates formed from metal plate but also to metal mask substrates having a metal or alloy surface in contact with a resist layer such as a laminate of a resin layer and a metal layer or a laminate having metal layers and a resin layer sandwiched therebetween. Even in the case of a resist layer formed from coating liquid containing materials to form a resist layer, the resist layer is under the same circumstances, as far as having low adhesion to a metal mask substrate.